-LRB- CNN -RRB- -- Sometimes it takes just one .

One person -- one idea -- to ignite a movement that changes lives .

Helping the millions of people who 've fled the war in Syria may seem a challenge far too big for small relief efforts . The U.N. calls it the worst humanitarian crisis in a generation . The needs are staggering .

And yet , for some people , it 's just not an option to do nothing .

I AM NOT A TOURIST

Tanya Khalil says she refuses to be a neutral observer . Her country , Lebanon , is taking in more Syrian refugees than any other -- nearly 1 million at last official count -- despite its tiny size .

The university student says it 's impossible to walk the streets of Beirut without seeing reminders of the suffering -- some refugees searching for food , others sleeping on sidewalks .

`` We can not think somebody else will take care of it , '' Khalil says . `` We are that somebody . Each and every one of us is that somebody and it is our duty towards one another to be caring and compassionate souls . ''

Khalil started a group called I AM NOT A TOURIST . The name was meant as a wake-up call to her fellow Lebanese -- that the Syrian crisis was now on their doorstep and they could no longer act like bystanders .

She could n't stand the thought of Syrian refugees shivering in brutally cold temperatures while she and her friends were sleeping in their warm beds .

They began collecting winter clothing and blankets for refugees in Akkar and the Bekaa Valley in north Lebanon . Khalil estimates 4,500 people donated items , filling 25 huge trucks . `` We ended up with more than 10,200 ` bags of love , ' '' she says .

Unlike other host countries , Lebanon has no formal refugee camps . Refugees there are scattered across some 1,600 locations , complicating aid distribution . Khalil partnered with established NGOs to help with logistics : Sawa for Syria and War Child Holland .

The United Nations estimates nearly 2.5 million Syrians are seeking shelter in Lebanon and in other neighboring states , but that accounts for only registered refugees . The true number could be much higher . And the crisis is only getting worse , as thousands of Syrians flee across the border each day .

Sweaters for Syria

Ranya Alkadamani was half a world away when she felt compelled to help . It all started with a conversation with her brother .

An Australian citizen living in Perth , Alkadamani has Syrian parents and family in Beirut . Her brother was heading to Beirut and asked if she had any old sweaters that he could take for a U.N. relief effort .

She said sure -- and then realized she could do something even bigger .

She sent an e-mail to work colleagues , asking if they had any sweaters to contribute . The note touched her boss , who called her and said he wanted to help start a campaign and that he would pay for shipping the sweaters .

It became known as Sweaters for Syria .

Alkadamani says she was overwhelmed by the response . She was worried that they would n't receive enough donations to fill even one container , but `` in two weeks , we pretty much filled the Salvation Army 's warehouse with 1,000 bags . ''

The campaign inspired people across Perth . One 6-year-old boy is said to have collected 600 sweaters on his own . `` When people know there 's something tangible that they can do to make a difference , they 'll do it , '' Alkadamani says .

She cried when she saw all the bags piled up in the warehouse -- 100,000 sweaters in all . `` Everyone was so generous and they cared as much as I did , and they 're not even Syrian , '' she says . `` That was overwhelming . ''

The bags were delivered to the UNHCR for distribution in Turkey and Jordan . Alkadamani visited Jordan this month , helping to hand out sweaters to refugees who were crossing the border .

She also visited Zaatari , a sprawling camp in the desert now home to nearly 125,000 refugees . That effectively makes it one of the largest cities in Jordan , and one of the largest refugee camps in the world .

Life is harsh there , a far cry from the comforts of home refugees left in Syria . The war does n't discriminate -- people from all walks of life have been forced to leave behind virtually everything they own . Alkadamani says she wants the world to understand that `` the people in those camps are just like you and me . ''

Khalil also stresses that point . She says Syrian refugees are just normal people -- from doctors to pharmacists to teachers -- with normal lives before the war tore their world apart .

You can do something too

Major aid agencies like UNHCR are overwhelmed with the sheer scale of this crisis , so grassroots efforts can play an important role in filling the gaps . Aid organizations also encourage groups to raise cash donations , as they provide the flexibility to meet particular needs by trained relief workers .

In all of these ways , individual efforts can make a difference in the face of enormous suffering .

It starts with a simple idea -- and the willingness to act .

You too can make an impact for Syrian refugees go to CNN.com / impact for large and small ways to help .

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Small , grassroots relief efforts help Syrian refugees survive a harsh winter .

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The Lebanese group `` I AM NOT A TOURIST '' collected thousands of `` bags of love '' in Beirut .

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Australians united to collect 100,000 `` Sweaters for Syria '' in Perth .

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You can make an impact for Syrian refugees . Go to CNN.com / impact for large and small ways to help .